Determining remaining useful life of rotating machinery including drive trains, gearboxes, and generators

Abstract

A method for predicting remaining useful life of a wind or water turbine or component determines in step ( 116 ) an EOH for the turbine or component and compares this in step ( 118 ) to an EOH limit obtained in step ( 114 ). This provides a simple approach to estimating remaining useful life, giving the turbine operator an indication of the condition of turbines or farms under management.

The invention claimed is: 
     
       1. A method for predicting remaining useful life of a wind or water turbine or a component thereof, the method comprising the following steps performed by a computer system:
 in advance of operation of the wind or water turbine, calculating one or more EOH (Equivalent Operating Hours) coefficients from damage to the wind or water turbine or a component thereof under rated operating conditions derived from design data and under a plurality of historical field operating conditions of a same duration, and storing the calculated one or more EOH coefficients in a non-transitory computer-readable medium; 
 determining an EOH for the wind or water turbine or component thereof according to the steps of: 
 collecting data from one or more sensors placed in or on the wind or water turbine or component thereof, the one or more sensors monitoring one or more of the field operating conditions of the wind or water turbine or component thereof; and 
 retrieving from the medium one or more of the EOH coefficients relating to each of the monitored one or more field operating conditions; 
 determining the EOH as a function of the collected data relating to the monitored one or more field operating conditions and the one or more EOH coefficients relating to the monitored one or more field operating conditions; 
 obtaining an EOH limit value for the wind or water turbine or component thereof; and 
 comparing the determined EOH and the EOH limit to produce a value for the remaining useful life of the wind or water turbine or component thereof; 
 wherein when the EOH is greater than the EOH limit, the method further comprises investigating for damage to the wind or water turbine or component thereof, the investigating including endoscope inspection of the wind or water turbine or component thereof. 
 
     
     
       2. The method according to  claim 1 , in which the step of assessing damage comprises providing one or more models selected from the group consisting of:
 a bearing skidding model; 
 a dynamic model; 
 a life model; 
 a nominal model of a gearbox, drive-train and/or generator of the wind or water turbine; 
 a model unique to a specific gearbox, drive-train and/or generator of the wind or water turbine including information on one or more manufacturing variations of one or more components of the gearbox, drive-train and/or generator; 
 a fully coupled finite element model comprising nodes with six degrees of freedom unique to a gearbox, drive-train and/or generator of the wind or water turbine; and 
 one or more meta-models, wherein the one or more meta-models are specific for each of the one or more components. 
 
     
     
       3. The method according to  claim 1 , in which each EOH coefficient is:
 a function of the damage under the rated operating conditions and damage under the field operating conditions of the same duration; 
 a function of a ratio of the damage under the rated operating conditions to the damage under the field operating conditions of the same duration; or 
 a ratio of the damage under the rated operating conditions to the damage under the field operating conditions of the same duration. 
 
     
     
       4. The method according to  claim 1 , in which the step of collecting data comprises one or more of the following:
 collecting historical data from the one or more sensors stored in the medium; 
 collecting data relating to one or more steady state operating conditions; 
 collecting data relating to one or more transient state operating conditions; 
 collecting data from the one or more sensors realtime during operation of the wind or water turbine or component thereof; and 
 collecting data from a condition monitoring system connected to the wind or water turbine or component thereof. 
 
     
     
       5. The method according to  claim 1 , in which the step of retrieving one or more EOH coefficients comprises one or more of the following:
 retrieving EOH coefficients relating to one or more steady state operating conditions; and 
 retrieving EOH coefficients relating to one or more transient state operating conditions. 
 
     
     
       6. The method according to  claim 1 , wherein the method further comprises:
 when the wind or water turbine or component thereof has damage: 
 refurbishing the wind or water turbine or component thereof; or 
 having irreparable damage, replacing the wind or water turbine or component thereof. 
 
     
     
       7. The method according to  claim 6 , wherein the method further comprises:
 when the wind or water turbine or component thereof is refurbished or replaced: 
 setting EOH of the wind or water turbine or component to zero. 
 
     
     
       8. The method according to  claim 1 , wherein the method further comprises:
 when the wind or water turbine or a component thereof has failed, and when the EOH is less than the EOH limit: 
 investigating for damage to the wind or water turbine or component thereof, comprising endoscope inspection and: 
 refurbishing the wind or water turbine or component thereof: or 
 having irreparable damage, replacing the wind or water turbine or component thereof. 
 
     
     
       9. The method according to  claim 8 , wherein the method further comprises:
 when the wind or water turbine or component thereof is refurbished or replaced: 
 setting EOH of the wind or water turbine or component to zero. 
 
     
     
       10. The method according to  claim 1 , in which the determined EOH is compared to a preset EOH limit for further forensic investigation, the preset EOH limit for further forensic investigation being less than the EOH limit, wherein if the determined EOH is less than the preset EOH limit, then no action is taken and the wind or water turbine continues operation, and wherein if the determined EOH is higher than the preset EOH limit for further forensic investigation, further investigations of the turbine are undertaken, comprising the endoscope inspection. 
     
     
       11. The method according to  claim 1 , wherein the step of investigating further includes at least one of vibration analysis or oil analysis. 
     
     
       12. A method for identifying a wind or water turbine or a component thereof for maintenance, the method comprising the following steps of performed by a computer system:
 determining an EOH (Equivalent Operating Hours) for the wind or water turbine or component thereof, comprising:
 collecting data from one or more sensors placed in or on the wind or water turbine or component thereof, the one or more sensors monitoring one or more field operating conditions of the wind or water turbine or component thereof; and 
 retrieving one or more EOH coefficients from a non-transitory computer-readable medium, relating to the one or more monitored field operating conditions and being calculated from damage to the wind or water turbine or a component thereof under rated operating conditions derived from design data and under a plurality of historical field operating conditions of a same duration; 
 determining the EOH as a function of the collected data relating to the monitored one or more field operating conditions and the one or more EOH coefficients relating to the monitored one or more field operating conditions; 
 
 setting thresholds for the collected data according to one or more ranges of EOH values; 
 comparing the collected data with at least one of the thresholds related to the determined EOH; 
 when the collected data is greater than the at least one threshold:
 identifying the wind or water turbine or component thereof for maintenance; and 
 investigating for damage to the wind or water turbine or component thereof by endoscope inspection, 
 wherein if damage is indicated, performing one of the following additional steps of:
 refurbishing the wind or water turbine or component thereof; 
 replacing the wind or water turbine or component thereof if the damage is irreparable; and 
 down-rating the wind or water turbine or component thereof. 
 
 
 
     
     
       13. The method according to  claim 12 , in which the operating collected data is vibration data. 
     
     
       14. The method according to  claim 12 , wherein the wind or water turbine or component thereof continues operation if damage is not indicated. 
     
     
       15. The method according to  claim 12 , wherein the step of investigating further includes at least one of vibration analysis or oil analysis.